Power system stabilizer and method

Abstract

A power system stabilizer includes: a sensor configured for sensing a signal representative of electromechanical oscillations of the power system; a controller configured for using the sensed signal for generating control signals for damping the electromechanical oscillations; and a damper including a damping converter and a resistor coupled to the damping converter, the damping converter being coupled to the power system through a power bus, the damping converter configured for using the control signals for damping the electro-mechanical oscillations.

1. A power system stabilizer, the stabilizer comprising:
 a sensor configured for sensing a signal representative of electro-mechanical oscillations of a power system; 
 a controller configured for using the sensed signal for generating control signals for damping the electro-mechanical oscillations; and 
 a damper comprising a damping converter and a resistor coupled to the damping converter, the damping converter being coupled to the power system through a power bus, the damping converter configured for using the control signals for damping the electro-mechanical oscillations, wherein the control signals provide dynamic stability and transient stability of the power system by damping the electro-mechanical oscillations, 
 wherein the damping converter comprises at least two insulated gate bipolar transistor (IGBT) modules, and 
 wherein the controller is configured for selectively switching IGBTs of the at least two IGBT modules simultaneously or sequentially. 
 
     
     
       2. The stabilizer of  claim 1  wherein the controller is configured for, during normal operation, generating control signals for damping the electro-mechanical oscillations, and, during transient operation, generating control signals for providing electro-mechanical braking through the damper. 
     
     
       3. The stabilizer of  claim 2  wherein, during normal operation, the damper is configured to provide a level of modulation of less than or equal to 10 Hz. 
     
     
       4. The stabilizer of  claim 2  wherein the resistor includes an inductance. 
     
     
       5. The stabilizer of  claim 1  wherein the damping converter further comprises a diode rectifier coupled in parallel to a capacitor which in turn is coupled to the at least two IGBT modules. 
     
     
       6. The stabilizer of  claim 5  wherein each of the at least two IGBT modules comprises three pairs of IGBTs with each pair of IGBTs being coupled in parallel to the other pairs. 
     
     
       7. The stabilizer of  claim 6  wherein the resistor comprises a plurality of resistors, and wherein each resistor is coupled across one IGBT of a respective pair of IGBTs. 
     
     
       8. The stabilizer of  claim 5  wherein the stabilizer is further configured for providing voltage ride-through capability. 
     
     
       9. The stabilizer of  claim 1  wherein at least some of the at least two IGBT modules are coupled in parallel. 
     
     
       10. The stabilizer of  claim 1  wherein each module has a power rating of no more than two MVA. 
     
     
       11. The stabilizer of  claim 1 , wherein the damper is embodied within an island or island-like power system. 
     
     
       12. A power system comprising
 a power system stabilizer, the stabilizer comprising: 
 a sensor configured for sensing a signal representative of electro-mechanical oscillations of the power system; 
 a controller configured for using the sensed signal for generating control signals for damping the electro-mechanical oscillations; and 
 a damper comprising a damping converter and a resistor coupled to the damping converter, the damping converter being coupled to the power system through a power bus, the damping converter configured for using the control signals for damping the electro-mechanical oscillations, wherein the control signals provide dynamic stability and transient stability of the power system by damping the electro-mechanical oscillations, wherein the damping converter comprises at least two insulated gate bipolar transistor (IGBT) modules, and wherein the controller is configured for selectively switching IGBTs of the at least two IGBT modules simultaneously or sequentially. 
 
     
     
       13. The power system of  claim 12 , wherein the power system comprises a power system configured for providing power to an assembly for obtaining oil, gas, or combinations thereof. 
     
     
       14. The power system of  claim 12 , wherein the power system comprises a wind turbine. 
     
     
       15. The power system of  claim 12  wherein the damper comprises a plurality of dampers at different locations within the power system. 
     
     
       16. The power system of  claim 12  wherein,
 the sensor comprises a plurality of sensors configured for sensing signals at different locations within the power system, 
 the controller comprises one or more controllers configured for using the sensed signals for generating control signals for damping the electro-mechanical oscillations, and 
 the damper comprises a plurality of dampers at the different locations. 
 
     
     
       17. The stabilizer of  claim 1  wherein the signal representative of electro-mechanical oscillations comprises an angular speed. 
     
     
       18. The stabilizer of  claim 12  wherein the signal representative of electro-mechanical oscillations comprises an angular speed. 
     
     
       19. A power system stabilizer, the stabilizer comprising:
 a sensor configured for sensing a signal representative of electro-mechanical oscillations of the power system; 
 a controller configured for using the sensed signal for generating control signals for damping the electro-mechanical oscillations; and 
 a damper comprising a damping converter and a resistor coupled to the damping converter, the damping converter being coupled to the power system through a power bus, the damping converter configured for using the control signals for damping the electro-mechanical oscillations; 
 wherein the damping converter comprises a diode rectifier coupled in parallel to a capacitor which in turn is coupled to an insulated gate bipolar transistor (IGBT) module; 
 wherein the damping converter comprises at least two IGBT modules; 
 wherein the stabilizer is further configured for providing voltage ride-through capability; 
 wherein the controller is configured for selectively switching IGBTs of the at least two IGBT modules simultaneously or sequentially.